Previous approaches to the assessment of work performance are based on a measurement model borrowed from the physical sciences that assumes all variation around a true value of an attribute is because of random measurement error. This may not be the case for work performance assessments. The level of performance exhibited on any given aspect of any job function may be determined by a combination of fixed abilities and the variable factors of personal motivation and situational constraints.
The failure of measurement models in conventional use to account for the non-error nature of variability in performance has led to appraisal methods that may be deficient in their coverage of the ways in which performances are differentiated. In addition, these appraisal methods may be deficient in that they are unable to restrict the range of performance for which workers are held accountable to that which is feasible to achieve. The latter deficiency, in addition to being a major source of unfairness in conventional appraisals, prevents conventional appraisal scores from being commensurate between job functions, jobs, or between the elements of any level to which job performance scores may be aggregated.
As a result of these and related deficiencies, dissatisfaction with conventional appraisal methods has been reported to be widespread among organizations in repeated surveys over the last 15 years. Therefore, a need exists for an appraisal method that overcomes some of the major deficiencies in conventionally used appraisal methods. Various aspects of the present invention meet such a need.